Methods and Systems for Manufacturing Composite Parts

ABSTRACT

Methods and apparatuses for manufacturing a composite part are provided. One method includes cutting a material into a plurality of pieces and marking each of the plurality of pieces of material with a unique indicium. This method also includes placing one of the pieces of material in a mold cavity, detecting a signal from the indicium on the piece of material, and verifying that the piece of material was placed in the mold cavity in the correct location based on the signal from the indicium. The placing, detecting, and verifying steps are performed for each of the plurality of pieces of material. The pieces of material are then molded together to form the composite part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to U.S.Provisional Patent Application No. 61/252,464, filed on Oct. 16, 2009,the contents of which are hereby incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION

A number of industries manufacture composite parts by cutting individualpieces from large rolls of material and assembling the composite part byarranging the pieces in a specific configuration within a mold cavity.For example, most related art methods of manufacturing composite windblades, or similar tooled composite parts for various industries such asaerospace and automotive, involve cutting individual pieces from a rollof material, and then placing the individual pieces of material in amold cavity according to a lay-up schedule. The individual pieces arethen bonded together to form a laminate with multiple laminated layers.This composite part may be custom-engineered to have specific mechanicalproperties appropriate for its intended use.

These related art methods of manufacturing wind blades and othercomposite parts are predominantly manual. For example, steps fromcutting the material to placing the individual cut pieces into the moldcavity may be performed manually by an operator. In composite partfabrication factories, operators typically cut the material, such asfiberglass, carbon fiber, or Kevlar, by hand or by computer cutter, andthen hand-write piece numbers on the cut pieces of material. However, itmay be disadvantageous to cut the pieces in the sequence in which theywill be used in the mold, because this does not allow for theoptimization of material use by closely packing the pieces within theroll of material. As a result, the pieces are generally cut in someother order that is better suited to maximizing the material yield. Thecut pieces may then be rolled up and stored until they are needed at themold. This requires a system of inventory storage and retrieval, whichis another manual process in widespread use today. Composite wind bladesor other large composite parts may incorporate 100's of cut pieces perpart, which can lead to problems in identifying and locating theappropriate cut pieces at the proper time.

In addition, an important aspect of the fabrication method is thelocation and orientation of each individual piece of material when it isplaced within the mold cavity. The integrity of a composite part designmay be compromised by errors in the laminate layup process, such as amissing piece, an incorrect piece, or a piece with an improper locationor orientation within the mold. Related art fabrication methods uselaser projectors to project an outline of the shape of each piece at thedesired location within the mold in the sequence dictated by thecomposite part design. An operator then acknowledges that each piece wasapplied properly in the mold by checking the inserted piece against theprojected image. Alternatively, the operator may use a hand-held camerasystem to verify the material type, ply presence, sequence, location,and fiber orientation of a piece within the mold. Both of these methodsrequire the operator to manually assess the actual placement of eachpiece as the pieces are placed within the mold.

Further, there is no independent verification that the correct piece wasinstalled, the piece was installed in the correct location, theorientation of the piece was correct, the piece was installed in thecorrect sequence, and the orientation of the fibers within the piece wascorrect. The related art fabrication method discussed above is subjectto operator error, because it relies on the operator's judgment toassess the placement of each piece within the mold. Because eachcomposite part includes many layers, any errors in the placement ofindividual pieces are very difficult to detect after the composite parthas been assembled. Any of the errors discussed above could cause thefailure of the composite part. In the aerospace industry and otherindustries that use composite parts, the cost of failure is very high,and it is therefore important, and in some cases required, toindependently validate each composite part's compliance with the designintent.

Recently, several new approaches for automating material placement inwind-blade and large aerospace part molds have been announced. Based onadvanced aerospace manufacturing technology, these systems are expectedto incorporate automated tape laying (ATL) or automated fiber placement(AFP) technology to directly build up material layers within a partmold, in addition to other mold preparation steps. Due to the formfactor of the parts, these proposed systems will need to be very large,and it is expected that they will be costly, complex, and difficult tomove. Also, these new approaches run counter to the desired wind bladeindustry trend of placing the blade manufacturing site near the end usesite, in order to circumvent the cost and logistical complexities oftransporting finished blades.

Therefore, it would be advantageous to automate many steps of thecurrent manual manufacturing system without the substantial costs andcomplexity of the proposed ATL and AFP machinery. In addition, it wouldbe advantageous to provide a method and system that could automaticallyvalidate the compliance of each composite part with the design intent.Further, it would be advantageous to develop a system that could beeasily deployed at any manufacturing site.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a method formanufacturing a composite part. The method includes cutting a materialinto a plurality of pieces and marking each of the plurality of piecesof material with a unique indicium. The method also includes placing oneof the pieces of material in a mold cavity, detecting a signal from theindicium on the piece of material, and verifying that the piece ofmaterial was placed in the mold cavity in the correct location based onthe signal from the indicium. The placing, detecting, and verifyingsteps are performed for each of the plurality of pieces of material. Thepieces of material are then molded together to form the composite part.

For each piece of material, the method may also include using light toproject an outline of the piece of material onto the mold cavity, andplacing the piece of material in the mold cavity within the projectedoutline. A portion of the light used to project the outline of the pieceof material may be reflected by the respective indicium as the signalfrom the piece of material.

The method may also include nesting the material by a computerizednesting engine before the cutting of the material into the plurality ofpieces. The nesting may include managing locations of seams within thepieces of material to be placed in the mold cavity based on acomputerized design of the composite part. In addition, the method mayinclude using an automated tracking system to identify and validate aroll of the material and verify that the material remains within itsuseful life before the cutting of the material into the plurality ofpieces, and additionally that the cut pieces are assembled into the moldand cured before they reach the end of their useful life or accumulatedtime out of cold storage. Further, for each piece of material, themethod may include winding the piece of material on a core tube by amulti-spindle winding machine after the cutting and marking of the pieceof material.

Before the placing of the plurality of pieces in the mold cavity, themethod may include determining a sequence according to which theplurality of pieces are to be placed in the mold cavity based on acomputerized design. Also before the placing of the plurality of piecesin the mold cavity, the method may include locating each of theplurality of pieces of material by communicating with the respectiveindicia on each of the pieces of material. The cutting, marking,detecting, and verifying may be performed by a controller and may bebased on a computerized design of the composite part.

Each indicium may include at least one of a symbol, a radio-frequencyidentification (RFID) tag, or a barcode. In addition, each indiciumcomprises a plurality of symbols that form a unique pattern.

For each piece of material, the method may also include verifying thatthe piece complies with a maximum cumulative time spent outside of coldstorage, based on the signal from the respective indicium. The markingmay include applying the respective indicium in registration with ageometry of the piece. Each of the plurality of pieces may be markedwith the respective indicium before or after the material is cut intothe plurality of pieces.

The method may also include recognizing that a piece of material wasplaced in an incorrect location in the mold cavity based on the signalfrom the respective indicium on the piece of material; comparing theincorrect location with the correct location; and feeding backinstructions for repositioning the piece of material based on theresults of the comparison. In addition, the method may include removinga protective layer on which the indicium was applied after verifyingthat the piece of material was placed in the mold cavity in the correctlocation for each piece of material; and scanning the mold cavity toverify that the protective layer was removed. Alternatively, top orbottom protective layers can be scanned after their removal from the cutpieces and logged to verify their removal from the mold.

According to another aspect of the invention, there is provided a methodof validating a placement of a piece of material within a mold cavity.The method includes marking the piece of material with an indicium;placing the piece of material in the mold cavity; detecting a signalfrom the indicium; and verifying that the piece of material was placedin the mold cavity in a correct location based on the signal from theindicium.

The method may also include verifying that the piece of material wasplaced in the mold cavity with a correct orientation with respect to themold cavity based on the signal from the indicium. In addition, themethod may include verifying that the piece of material was placed inthe mold cavity with a correct fiber orientation based on the signalfrom the indicium. Further, the method may include verifying that thepiece of material was placed in the mold cavity in a correct sequencewith respect to other pieces of the material based on the signal fromthe indicium. Additionally, the method may include verifying that thepiece of material complies with a maximum cumulative time spent outsideof cold storage based on the signal from the indicium.

The signal from the indicium may indicate an actual location of thepiece of material, and the verifying that the piece of material wasplaced in the mold cavity in the correct location may include comparingthe actual location of the piece of material with a target location ofthe piece of material based on a design of the composite part. Thetarget location may be stored within the indicium.

According to yet another aspect of the invention, there is provided asystem for manufacturing a composite part. The system includes a cutterthat cuts pieces of material; an applier that applies a unique indiciumto each piece of material; a projector that projects an outline of eachpiece of material onto a mold cavity; a detector that receives a signalfrom the respective indicium on each piece of material; and a processorthat analyzes the signals to verify that each piece of material wasplaced in the mold cavity in a correct location.

The system may also include a multi-spindle winding machine that iscoordinated with an output of the cutter and that winds each piece ofmaterial on a core tube. The applier may include at least one of aprinter that applies the respective indicium directly to the piece ofmaterial, or a labeler that applies a label (visual or RFID) on whichthe respective indicium is printed to the piece of material.

According to a further aspect of the invention, there is provided asystem for manufacturing a composite part. The system includes means forcutting pieces of material; means for applying a unique indicium to eachpiece of material; means for projecting an outline of each piece ofmaterial onto a mold cavity; means for receiving a signal from therespective indicium on each piece of material; and means for analyzingthe signals to verify that each piece of material was placed in the moldcavity in a correct location.

According to a further aspect of the invention, there is provided acomputer-readable medium comprising computer instructions executable bya processor to cause the processor to perform a method of validating aplacement of a piece of material within a mold cavity. The methodincludes marking the piece of material with an indicium; detecting asignal from the indicium after the piece of material has been placed inthe mold cavity; and verifying that the piece of material was placed inthe mold cavity in a correct location based on the signal from theindicium.

Other objects, advantages, and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a manufacturing process according to an exemplaryembodiment of the present invention;

FIG. 2 shows a system and a corresponding workflow according to anexemplary embodiment of the invention; and

FIG. 3 shows the Gerber Technology DCS-3600 single-ply industrialmaterial cutter that may be used in an exemplary embodiment of theinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1 shows a composite part manufacturing process according to anexemplary embodiment of the present invention. This method utilizes atwo-dimensional representation of the individual layers and/or atwo-dimensional representation of the individual pieces to be cut. Togenerate the two-dimensional representations, a three-dimensionalcomputer-aided-design (CAD) program such as Dassault Systemes' CATIAComposites Design is typically used by the composite part designers toaccurately model and predict the performance of a composite part design;however, any suitable CAD system may be used. This computer simulationof the part design is used to avoid the pitfalls that have plaguedprevious manual trial-and-error manufacturing processes for compositepart manufacturing, such as wind blade fabrication. For example, bladefailure studies performed by Sandia National Labs have revealed thatmanufacturing errors, including bad bonds, voids, delamination, poorlaminate schedules, waviness, leading edge erosion, and trailing edgesplits were responsible for a large number of required field bladereplacements of wind blades that were manufactured by the manualtrial-and-error wind blade manufacturing processes.

As shown in FIG. 1, the composite manufacturing process according to anexemplary embodiment of the invention begins with the layout 110 of thematerials. Starting with the two-dimensional representation ofindividual single layer pieces, the designer or design program maydictate the material of choice based on a variety of design factors,including strength, weight, and tensile member orientation. Thetwo-dimensional piece representations are then grouped according to thecommon material type and thickness of the material from which they willbe cut. For example, the material may be fiberglass, carbon fiber,Kevlar, or any other material that is suitable for composite partmanufacturing. The composite manufacturing process shown in FIG. 1 mayalso apply to core materials, such as wood or foam, that are placedbetween the pieces in the mold cavity to form a non-solid compositepart. These core materials are typically cut with a different type ofcutter, such as a router, saw, or bevel cutter. However, each of thesteps of the method described herein can also be applied to the corematerials.

Piece nesting, joint management, and layer management are performedduring the layout 110. Nesting is an operation in which single layerpieces to be produced from the same material are grouped together tomake the best possible use of the material. For example, the pieces tobe cut from a particular material may be superimposed on a roll of thematerial, such that the portion of unused and discarded material isminimized. Nesting has a significant impact on the material yield.Because the materials typically represent a significant percentage ofthe cost of a composite part, it is important to control the cost of thematerials. For example, in the case of wind blades, the materials mightrepresent as much as 60% of the total cost of a blade.

Further, for structural reasons, there are some regions within acomposite part where seams are allowable and other regions where seamsare forbidden. A seam occurs when a piece overlaps the edge of a roll ofmaterial, such that a portion of piece is cut from the bottom edge ofthe roll, and the remainder of the piece is cut from the top edge of thenext roll. Joint management determines where seams are located withinthe composite material, and prevents seams from occurring in the regionswhere they are prohibited. Similarly, structural considerations mayprohibit coincident seams on successive layers. Layer managementdetermines where seams are located from layer to layer.

In related art composite part manufacturing processes, many of the stepsare performed manually by an operator. For example, a related art manualmanufacturing process performs a manual layout that includes manualpiece nesting, manual joint management, and manual layer management.However, manual nesting is labor-intensive, unreliable, and notrepeatable. This leads to problems in the manual layout process, whichcan have a substantial impact on the final part quality and reliability.The manual layout process also suffers from the inefficiency of notpredictably knowing where any given piece may cross over the end of aroll of material. For example, if a piece overlaps the edge of a roll,it may be necessary to discard the material allocated to that piece if aseam is prohibited by the joint management or layer managementprocesses.

In contrast, according to exemplary embodiments of the invention, thelayout 110 may include automated piece nesting, automated nesting ofmultiple rolls, automated in-process re-nesting, automated jointmanagement, and automated layer management. The automated nesting usescomputer nesting engines similar to those used in the garment industryand other industries. The automated nesting begins by superimposing thepieces called for in the computerized design over the known dimensionsof the rolls of material. The computer nesting engines can run throughnumerous scenarios with cut piece data to optimize the use of materialsby re-positioning pieces according to the design rules. Within thedesign rules for fiber orientation, pieces may be rotated, translated,or swapped out with other pieces, which may allow closer packing withina given roll's width and length. Automated nesting may producesignificant savings in material yields, as it accounts for the shapes ofpieces, as well as rules for joints and splices in material, multiplerolls, and materials with non-uniform thickness due to their multi-axialconstruction. Automated nesting may also perform re-nesting if thelength of a roll of material is found to be different than anticipated.In addition, automated joint and splice management can establish rulesto allow or disallow a seam in a specific part and/or adjust the seamlocation accordingly by re-nesting or shifting parts in anticipation ofthe roll's end.

Referring back to FIG. 1, the composite part manufacturing process thenperforms an unwind process 120. A related art manual process includesmanually identifying a roll of material from inventory, manuallyvalidating that the proper roll is used, and manually validating thatthe material is within its useful life by visually checking the “use-by”date, and for pre-preg composite materials, manually recognizing thecumulative time that any given roll has been out of cold storage tocomply with established limitations on elevated temperature usage priorto curing. A pre-preg material is one in which a resin is built into thematerial, such that the material has a limited shelf life, and may bekept at room temperature only for a limited time. The manual unwindprocess also requires the operator to pull a roll of material frominventory and manually unwind the roll to lay the material flat withouttension or wrinkles onto a cutting table, where it is later hand-cutaccording to pattern templates.

In contrast, according to exemplary embodiments of the invention, theunwind process 120 may include automatically identifying a roll ofmaterial from inventory, automatically validating that the proper rollis used, and automatically validating that the material is within itsuseful life. The roll is automatically identified based on the job andthe pieces to be cut within the computerized design. For example, arewritable RFID chip may be placed on each roll to track the roll inreal time. The RFID chip may indicate various parameters of thematerial, such as the remaining length of the material on the roll,material type, thickness, weight, resin properties, as well as thecumulative time that the roll has been out of cold storage. The operatormay then load the validated roll into a machine that automaticallyunwinds the roll to coordinate with the cutter's conveyor that alignsand feeds the material.

Next, the composite manufacturing process cuts and marks the pieces ofmaterial in process 130. In a related art manual composite manufacturingprocess, templates are produced to serve as masters for each piece. Theoperator arranges these templates on top of unrolled materials, whichhave been laid out onto a cutting table during the unwind process 120.The pieces are then cut to the general shape of the template. During themanual cut process, individual pieces are cut by hand and then test-fitin the mold, where manual nip-and-tuck modifications take place. Themanual cut process includes manually locating the proper template,manually cutting the pieces, and manually returning the template tostorage. Each cut piece is later hand-marked with a piece number.

In contrast, according to exemplary embodiments of the invention, theprocess 130 includes automatically cutting and automatically markingeach of the pieces. As described in further detail below, a controllerrefers to the computerized design and controls the cutter toautomatically cut the appropriate pieces needed for the design. Thecutter used in the automated process 130 may include an interchangeableultrasonic cutting head to allow cutting stacks of bound and uncuredmaterials or any number of other cutting technologies, such asreciprocating blade, rolling blade, and driven blade technologies. Forexample, single-ply pre-preg materials, multi-ply dry stacks, and/ormulti-ply pre-preg stacks may be cut. The automated process 130 mayprovide high throughput and material yield, along with a repeatablepiece shape.

Exemplary embodiments of the present invention may include a mechanismto automatically mark each of the pieces with a unique indicium thatincludes identifying information according to established rules. Atleast one component of the respective indicium includes information thatuniquely identifies the marked piece. For example, an indicium mayinclude a plurality of symbols, such as circular dots and/or crosshairs, that are printed as a pattern such that no two pieces haveidentical patterns. Alternatively, or in addition, an indicium mayinclude an RFID tag or a barcode in which identification information isstored. The pattern and/or the identification information may be storedwithin a look-up table that associates the marked piece with itsposition within the composite part. Accordingly, each unique patternand/or identification information is recognized by the system controlleras a specific piece to be positioned at a specific location within themold cavity. According to this method, pieces that are not cut insequence can be automatically located and sent to the mold at theappropriate time.

The indicium may indicate the serial number, manufacturing data, anddate of manufacture of the piece of material. The indicium may alsoindicate the piece number, the location where the piece is stored, theage of the piece, the “use by” date of the piece, the mold number, thesequence number, and the desired location and orientation of the piecewithin the mold. In addition, the indicium may indicate the cumulativetime that the piece has been out of cold storage.

A symbol within the indicium is advantageously applied at a preciselocation on the piece of material such that the symbol is registeredwith the specific geometry of the piece of material. This provides areference point for the location and orientation of the piece once it isplaced within the mold. For example, an ink jet head may be used to markthe piece with ink on its protective backing, or where acceptable,directly on the material itself. Where there is no backing or the pieceis to be marked on an exposed surface, a removable label may be used formarking to prevent contamination. The label may be pre-printed, or thelabel may be marked after it is applied to the piece.

According to exemplary embodiments of the invention, the piece may becut before it is marked with the indicium. Alternatively, the piece maybe marked with the indicium before it is cut from the roll of material.In this embodiment, a cutter-mounted scanning system recognizes thelocation of the unique indicium when the roll of material is placed onthe cutter surface, and the cutter cuts the piece in exact registrationwith the indicium. For example, the laser projector discussed below maybe used to recognize the indicium.

Referring back to FIG. 1, during the rewind process 140, the larger cutpieces are rewound onto core tubes, wound without core tubes, or leftflat. In a related art manual rewind process, the cut pieces aremanually labeled and manually rewound onto the core tubes. The cutpieces may be relatively tender and must be handled carefully to preventdamage and contamination. Generally, cut pieces of any appreciable sizeare manually wound up on core tubes, and then manually moved to storageor directly to the mold. In contrast, the automated rewind processaccording to exemplary embodiments of the invention replaces the manualwinding of the cut pieces with an automated multi-spindle windingmachine that is synchronized with the output of the cutter. The piecesare automatically marked according to a set of rules for which windingarm should be used to prevent bottlenecks at the winding station, andwound simultaneously if they were laid out in parallel. This marking maybe part of the unique indicium, or an additional printed alphanumericannotation, bar code, RFID tag, or any other visual or machine readablemark.

Once the pieces have been rewound, they may receive additional marks orlabels to aid in their identification and relocation from storage. Theyare then placed in an inventory during process 150. The requirements fortracking the inventory are somewhat different for manufacturersutilizing pre-preg materials than for those using dry materials, due tothe limited shelf life of the pre-preg materials. For example, it isadvantageous to track the cumulative time that a pre-preg material hasbeen out of cold storage. However, regardless of which type of materialis used, some type of cut piece storage, inventory identification, andretrieval is required. In a related art manual inventory process, thematerial attributes are not tracked, which can lead to excessive labor,confusion, and a significant possibility of a lost or incorrect pieceutilization that can result in a blade failure. In contrast, theautomated inventory process according to exemplary embodiments of theinvention provides for the automated identification and tracking ofvariables such as piece number, piece storage location, piece age or“use by” date, mold number, piece sequence, and generalized piecelocation within the mold. Specifically, the components of the printedindicium can be used to store and retrieve these variables, as well asother variables that could be added in the future.

The inventory is utilized in retrieving the pieces needed for the layup160. A related art manual layup process includes manually determiningthe piece sequence, manually locating the piece to be placed from theinventory, manually identifying the desired position of the piece withinthe mold, manually placing the piece within the mold, and manuallyreporting the placement of the piece. During this process, athree-dimensional image of the two-dimensional piece may be projectedinto the mold by a laser projector to indicate the location for theoperator to place the piece in the mold; however, the use of a laserprojection system for aligning manually cut pieces does not take fulladvantage of the value of such a system due to the imprecision of themanually cut pieces.

In contrast, an automated layup process according to exemplaryembodiments of the invention includes automatically determining thepiece sequence, automatically locating the piece to be placed from theinventory, and automatically identifying the desired position of thepiece within the mold. The piece sequence may be automaticallydetermined by referring to the computerized design. The piece to beplaced may be automatically located in the inventory by scanning thearea where the cut pieces are stored and identifying the proper piece byreceiving a signal from a component of the indicium, such as a symbol oran RFID tag. A controller may then automatically identify the desiredposition of the piece within the mold by controlling the laser projectorto project a three-dimensional image of the two-dimensional piece intothe mold. The operator then places the piece into the mold based on theguidance from the laser projector.

Once the piece has been placed within the mold, the position of thepiece within the mold may be automatically detected by receiving asignal from a component of the indicium, such as a symbol or an RFIDtag. For example, visible laser light from the laser projector that isreflected by a symbol on the piece that was applied as a reference pointor series of points or targets may be detected to ascertain the preciselocation of the piece within the mold. This actual location may then becompared with the target location based on the computerized design. Thetarget location may be stored within the indicium and/or in a computermemory that is readable by the controller. The controller may determinethe direction and magnitude of the variation of the actual location fromthe target location, and provide this information to the operator sothat the operator can move the piece to correct its position. Thisprocess may be repeated until the piece is correctly positioned at thetarget location.

Additional geometrical aspects may also be automatically determinedbased on the signal from the indicium, including the orientation of thepiece with respect to the mold and the orientation of fibers within thepiece. Again, the actual orientation of the piece may be compared with atarget orientation based on the computerized design, and the controllermay indicate how the operator should move the piece to correct theorientation. Further, additional information may be read from the symboland/or RFID tag, such as the serial number, manufacturing data, date ofmanufacture, piece age or “use by” date, mold number, and piecesequence.

The indicium may be printed with ink that reflects the laser light fromthe projector, and a sensor may be coincident with or mounted near thelaser source of the projector to detect the light reflected by theindicium. Alternatively, any other suitable technology may be used torecognize the indicium and extract its embedded information, such asRFID, ultrasound, induction, magnetism, infrared light, and/or a camerawith image processing capability.

As discussed above, the automated layup process utilizes the signal fromthe indicium to validate that the correct piece was installed, the piecewas installed in the correct location within the mold cavity, the piecewas installed in the correct orientation with respect to the moldcavity, the piece was installed in the correct sequence, and the fiberorientation of the piece was correct. Once these parameters are verifiedas correct, the validation is logged for later reference, and thecorrect placement of the piece is automatically reported. Therefore, theautomated composite part manufacturing process provides independentpiece validation and other higher level features, while improving theaccuracy and efficiency of the manufacturing process. Once each piecehas been correctly positioned within the mold cavity, the pieces arebonded together to form a laminate having multiple laminated layers.

One failure mechanism of composite parts is the inadvertent failure toremove a plastic protective backing material from a cut piece. Allpre-preg materials are shipped from the supplier with a plasticprotective layer, which is often placed on top and bottom sides of thematerial. According to exemplary embodiments of the invention, theunique indicium may be printed on the top surface of the protectivelayer on the top side of the material. Once a piece has been placed inthe mold and verified to be in the correct location, the protectivelayer is removed from the top side of the material. The laser projectoror any other suitable component may then be used to scan the mold toconfirm that the top protective layer was removed from the piece in themold. This ensures that no top protective layers are inadvertently lefton the pieces before forming the composite part.

Further, exemplary embodiments of the invention may include a method ofensuring that no bottom protective layers remain on the pieces beforeforming the composite part. For example, another indicium may be printedon the bottom side of the piece, or a label may be applied to the bottomside of the piece. The bottom protective layer is removed from the piecebefore placing the piece into the mold, and the indicium from the bottomprotective layer is scanned and logged into the system to provide arecord of the removal of the bottom protective layer before placing thepiece into the mold. Similarly, the top protective layers can be scannedafter removal from the part in the mold and logged into the system forverification to assure complete removal of all protective layers.

The composite part manufacturing process described above usespredominantly automated steps throughout the process. However, exemplaryembodiments of the invention also include modifying one or more steps ofa related art manual composite part manufacturing process by replacingcertain manual steps with automated steps. For example, the cutting andmarking of the pieces in process 130 could be automated as describedabove, while the rewinding 140 of the pieces is performed manually.

According to an exemplary embodiment of the invention, there is provideda computer-readable medium encoded with a computer program formanufacturing composite parts. The term “computer-readable medium” asused herein refers to any medium that participates in providinginstructions for execution. Common forms of computer-readable mediainclude, for example, a floppy disk, a flexible disk, a hard disk,magnetic tape, any other magnetic medium, a CD-ROM, any other opticalmedium, punch cards, paper tape, any other physical medium with patternsof holes, a RAM, a PROM, an EPROM, a FLASH-EPROM, any other memory chipor cartridge, and any other non-transitory medium from which a computercan read.

FIG. 2 shows an exemplary system in conjunction with a workflow that maybe used in accordance with the present invention. As shown in FIG. 2,exemplary embodiments of the present invention may utilize a softwarearchitecture that allows incorporation of a variety of manufacturingprocess features necessary for automation in manufacturing wind bladesor other composite parts. Various work cell functions can be linked tocustomer equipment for pre- and post-processing. For example, a systemconfiguration specific to wind blade manufacturing may use a single plycutter that incorporates a conveyor cutting bed, such as the GerberTechnology DCS-3600 shown in FIG. 3. The DCS-3600 is a single-plyconveyor material cutter configured for industrial markets.

The system architecture allows for multiple cutting stations andadditional operations that may include material roll feeding (unwindingroll goods to present them in a properly aligned, stress-free conditionto the cutter), piece marking (ink jet printing and/or label printingand application), and re-winding (rolling pieces onto core tubes forease of storage and handling). For example, as shown in FIG. 2, theworkflow 3 may progress through the work cells 200 from a feeder 220 toa winder 260, a part manager 270, and a laser projector 280. A processmanager 290 may be connected to work cell controllers 210 within thework cells 200 via an Ethernet interface 300. The process manager 290may include a customized GUI 420 to assist with tool allocation pathplanning 430. The computerized design is stored on the process manager290 to enable the automated control of the composite part manufacturingprocess discussed above.

The workflow 3 may include nesting changes 440 that account for materialgeometric anomalies, defects, joints, and thicknesses. The workflow 3may then proceed with renesting 310 and part splitting and/or jointmanagement 320. A material end sensor 330 may be used before or afterthe cutting begins to determine the location of the end of the roll ofmaterial. Slitters or cutters 230 may perform ultrasonic cutting orother methods of cutting 340, tool calibration 350, cutting whileconveying 360, and/or conveyor registration 370. The work cells 200 mayhave a multi-cell control 380. A label and/or inkjet printer 390 mayapply the indicia to the cut pieces. External communications 400 occurbetween the work cells 200 and the winder 260.

Another exemplary embodiment of the present invention utilizes a modularmanufacturing system architecture based on software that enables rapiddeployment of new product configurations for unique new industrialmarket applications. This software platform may organize software intoareas of commonality and variability across a set of similar products.Services or components common to a set of products form a library ofmature core assets that can be reused for each new product, therebyshortening the time to market.

Architectural patterns and principles that may be employed consistentlythroughout the system promote reuse by making components easilyconnectable. A common infrastructure may provide standard mechanisms forpassing information, such as synchronous and asynchronous control flowand event notifications. This software platform may allow for simplemodular connectivity for any number of different peripherals to beintegrated into a production manufacturing system centered on acomputer-driven cutter configured for the idiosyncrasies of each newapplication.

For example, the modular manufacturing system may include a plurality ofmechanical processing elements designed to transform materials in acontinuous convey fashion. The processing elements may include one ormore cutting devices for cutting textiles and other flexible materials;printers for identification of parts, colorizing, or graphic colorprinting; cameras, sensors, and laser projectors for edgeidentification, part identification, feature recognition, and partsequencing; and/or other material transport or processing elements. Theprocess or transport elements may be configured for any number ofmaterial widths, or grouped with various elements to increase overallsystem throughput.

The modular manufacturing system may directly couple with an endlessupstream source of material such as an extruder, in which case it mayincorporate a material accumulator to allow for any time variationsbetween material processing and upstream material feed. Alternatively,the system can process individual material elements, such as leatherhides or material on rolls, with minimal roll change disruption into cutparts. In this case the modular manufacturing system could includeprocessing mechanisms to unwind supply rolls. In either case, the systemcoordinates rolling of material at the output terminus.

The modular manufacturing system may incorporate a modular control toenable custom configuration of individual elements in any number or inany sequence without the need for re-writing control logic code. Thiscontrol can manage data in a real-time fashion and is capable ofcontinuous processing of variable data on unique and ever-changinginput. For example, the system may custom-nest individual parts for aseries of leather hides based on upstream data obtained from a scannerelement within the system.

Exemplary embodiments of the present invention may provide means toaddress the unique requirements of the composites industry, includinghigh volume or high throughput material handling, process management forpiece identification and inventory management, optimized productivitythrough piece sequencing, and improved material utilization throughimproved nesting with sensitivity for joint and material layermanagement. The described methods and systems may have the hardware andsoftware control hooks to allow integration of roll goods feeding,rewinding of cut pieces, piece marking, and inventory management. Aprocess similar to the exemplary embodiments described above may be usedto manufacture a composite material in any industry.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1. A method of manufacturing a composite part, the method comprising:cutting a material into a plurality of pieces; marking each of theplurality of pieces of material with a unique indicium; for each pieceof material, placing the piece of material in a mold cavity, detecting asignal from the respective indicium, and verifying that the piece ofmaterial was placed in the mold cavity in a correct location based onthe signal from the respective indicium; and molding the pieces ofmaterial together to form the composite part.
 2. The method recited inclaim 1, further comprising, for each piece of material, using light toproject an outline of the piece of material onto the mold cavity, andplacing the piece of material in the mold cavity within the projectedoutline.
 3. The method recited in claim 2, wherein, for each piece ofmaterial, a portion of the light used to project the outline of thepiece of material is reflected by the respective indicium as the signalfrom the piece of material.
 4. The method recited in claim 1, furthercomprising nesting the material by a computerized nesting engine beforethe cutting of the material into the plurality of pieces.
 5. The methodrecited in claim 4, wherein the nesting comprises managing locations ofseams within the pieces of material to be placed in the mold cavitybased on a computerized design of the composite part.
 6. The methodrecited in claim 1, further comprising using an automated trackingsystem to identify and validate a roll of the material and verify thatthe material remains within its useful life before the cutting of thematerial into the plurality of pieces.
 7. The method recited in claim 1,further comprising, for each piece of material, winding the piece ofmaterial on a core tube by a multi-spindle winding machine after thecutting and marking of the piece of material.
 8. The method recited inclaim 1, further comprising: before the placing of the plurality ofpieces in the mold cavity, determining a sequence according to which theplurality of pieces are to be placed in the mold cavity based on acomputerized design.
 9. The method recited in claim 1, furthercomprising: before the placing of the plurality of pieces in the moldcavity, locating each of the plurality of pieces of material bycommunicating with the respective indicia on each of the pieces ofmaterial.
 10. The method recited in claim 1, wherein the cutting,marking, detecting, and verifying are performed by a controller and arebased on a computerized design of the composite part.
 11. The methodrecited in claim 1, wherein each indicium comprises at least one of asymbol, a radio-frequency identification (RFID) tag, or a barcode. 12.The method recited in claim 1, wherein each indicium comprises aplurality of symbols that form a unique pattern.
 13. The method recitedin claim 1, further comprising, for each piece of material, verifyingthat the piece complies with a maximum cumulative time spent outside ofcold storage, based on the signal from the respective indicium.
 14. Themethod recited in claim 1, wherein the marking comprises applying therespective indicium in registration with a geometry of the piece. 15.The method recited in claim 1, wherein each of the plurality of piecesis marked with the respective indicium before the material is cut intothe plurality of pieces.
 16. The method recited in claim 1, furthercomprising, for a piece of material: recognizing that the piece ofmaterial was placed in an incorrect location in the mold cavity based onthe signal from the respective indicium on the piece of material;comparing the incorrect location with the correct location; andrepositioning the piece of material based on the results of thecomparison.
 17. The method recited in claim 1, further comprising, foreach piece of material: after verifying that the piece of material wasplaced in the mold cavity in the correct location, removing a protectivelayer on which the indicium was applied; and scanning the mold cavity toverify that the protective layer was removed.
 18. A method of validatinga placement of a piece of material within a mold cavity, the methodcomprising: marking the piece of material with an indicium; placing thepiece of material in the mold cavity; detecting a signal from theindicium; and verifying that the piece of material was placed in themold cavity in a correct location based on the signal from the indicium.19. The method recited in claim 18, further comprising verifying thatthe piece of material was placed in the mold cavity with a correctorientation with respect to the mold cavity based on the signal from theindicium.
 20. The method recited in claim 18, further comprisingverifying that the piece of material was placed in the mold cavity witha correct fiber orientation based on the signal from the indicium. 21.The method recited in claim 18, further comprising verifying that thepiece of material was placed in the mold cavity in a correct sequencewith respect to other pieces of the material based on the signal fromthe indicium.
 22. The method recited in claim 18, further comprisingverifying that the piece of material complies with a maximum cumulativetime spent outside of cold storage based on the signal from theindicium.
 23. The method recited in claim 18, wherein the signal fromthe indicium indicates an actual location of the piece of material, andthe verifying that the piece of material was placed in the mold cavityin the correct location comprises comparing the actual location of thepiece of material with a target location of the piece of material basedon a design of the composite part.
 24. The method recited in claim 23,wherein the target location is stored within the indicium.
 25. A systemfor manufacturing a composite part, the system comprising: a cutter thatcuts pieces of material; an applier that applies a unique indicium toeach piece of material; a projector that projects an outline of eachpiece of material onto a mold cavity; a detector that receives a signalfrom the respective indicium on each piece of material; and a processorthat analyzes the signals to verify that each piece of material wasplaced in the mold cavity in a correct location.
 26. The system recitedin claim 25, further comprising a multi-spindle winding machine that issynchronized with an output of the cutter and that winds each piece ofmaterial on a core tube.
 27. The system recited in claim 25, wherein theapplier comprises at least one of a printer that applies the respectiveindicium directly to the piece of material, or a labeler that applies alabel on which the respective indicium is printed to the piece ofmaterial.
 28. A system for manufacturing a composite part, the systemcomprising: means for cutting pieces of material; means for applying aunique indicium to each piece of material; means for projecting anoutline of each piece of material onto a mold cavity; means forreceiving a signal from the respective indicium on each piece ofmaterial; and means for analyzing the signals to verify that each pieceof material was placed in the mold cavity in a correct location.
 29. Acomputer-readable medium comprising computer instructions executable bya processor to cause the processor to perform a method of validating aplacement of a piece of material within a mold cavity, the methodcomprising: marking the piece of material with an indicium; detecting asignal from the indicium after the piece of material has been placed inthe mold cavity; and verifying that the piece of material was placed inthe mold cavity in a correct location based on the signal from theindicium.
 30. The method recited in claim 1, further comprising: foreach piece of material, after verifying that the piece of material wasplaced in the mold cavity in the correct location, removing a protectivelayer on which the indicium was applied; and scanning each of theremoved protective layers to verify that none are left in the mold.